Description
Product details:
Cytolytic activity is an important process for eliminating intracellular pathogens and cancer cells. Cytotoxicity Assay Kit (CFSE, 7-AAD) (ab270780) allows you to assess cytolytic activity in cell culture.
Older methods to assess NK cytolytic activity include measuring the release of lactate dehydrogenase, and more commonly, the release of radioactive
Cr from lysed target cells. Unfortunately, these techniques have several drawbacks. Traditional enzyme-release assays are often skewed by the large number of necrotic effector cells. Problems associated with
Cr release methods include high spontaneous leakage resulting in high backgrounds, high cost, short half-life, and the health risks due to exposure to radioactive material.
Flow cytometric assays have been developed to overcome some of the difficulties associated with older assays like lactate dehydrogenase and
Cr release assays. One such early version involved the detection of NK cytotoxicity activity by staining target cells with the green fluorescent dye, F-18, in combination with the DNA intercalating dye, propidium iodide . Since then, a red fluorescent membrane dye, PKH-26, has been used in preference to F-18, and in combination with the viability probe, TO-PRO-3 iodide4-7. However, despite correlations of greater than 95% when compared with the
Cr release assay, the PKH-26 method is problematic. It is difficult to use at a constant concentration, leading to unreliable staining, and the staining procedure requires multiple steps, often decreasing the viability of the target cells.
Cytotoxicity Assay Kit (CFSE, 7-AAD) includes two fluorescent reagents: CFSE and 7-AAD. CFSE, a green fluorescing cellular stain, is utilized to identify the target cell population. The unstained effector cells are added and incubated with the target cells. 7-AAD, a red fluorescing live/dead stain, is then added to stain all necrotic cells red by binding to the DNA of membrane-compromised cells. The target cell and effector cell populations can then be easily distinguished, and flow cytometry easily identifies live and necrotic cells.
Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage conditions--20°C, Appropriate long-term storage conditions--20°C, Storage information--20°C
